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At least 469 records · Page 26Linked to original sources
PubMed1984

In vivo effect of amiodarone, thiocyanate, perchlorate and goitrin on thyroxine deiodination in rat liver.

The bile duct of male Wistar rats weighing 350 g was cannulated with polyethylene tubing under pentobarbiturate anesthesia and biliary excretion of thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3) and 3,3'-,3,5- and 3',5'-diiodothyronine (3,3'-T2, 3,5-T2 and 3',5'-T2, respectively) was estimated in 2 h samples of bile with the aid of specific radioimmunoassay. In each animal the excretion of appropriate compounds for 2 h after intravenous injection of various drugs was expressed as per cent of that during 2 h control period before the injection. The results obtained in individual groups of animals were compared to control group which was injected saline before the second bile collection period. The injection of amiodarone (15 mg kg-1) resulted in significant decrease of T3, rT3, 3,3'-T2 and 3,5-T2 excretion and that of thiocyanate (SCN-; 50 mg kg-1) resulted in significantly increased excretion of T4, while that of T3 and 3,5-T2 was significantly decreased. Goitrin (L-5-vinyl-2-oxazolidinethione; 6 mg kg-1) and perchlorate (ClO4-; 50 mg kg-1) showed only slight effects. It was concluded that amiodarone and thiocyanate in the doses used inhibited the conversion of T4 to T3 in vivo immediately after the administration.

Amiodarone↗
PubMed1980

Biological damage in spleen by iodine-125 in potassium perchlorate blocked thyroid of rats.

Studies on spleen have been performed following administration of iodine-125 in perchlorate-treated rats. Although DNA levels did not change appreciably, there was a significant decrease in total RNA following incorporation of iodine-125. Associated with the changes in RNA, there was a significant rise in acid phosphatase and total as well as Mg-dependent ATPases. Increased activity of acid phosphatase seems to be related to the loss of lymphocytes, whereas the rise in ATPase appeared to be associated with cells of red pulp of spleen. It is suggested that damage to the spleen after administration of iodine-125 is due to the Auger effect.

Acid Phosphatase↗
PubMed1980

An evaluation of prepackaged columns for the separation of carcinoembryonic antigen from perchloric acid: concise communication.

Commerically available Sephadex buffer-exchange columns for the separation of carcinoembryonic antigen (CEA) from perchloric acid were evaluated. Elution patterns of individual columns were found to be variable, but separation of acid from CEA could be accomplished. Repeatability of replicate elutions and agreement with dialysis results were acceptable. Nevertheless, the method is excessively time-consuming and inefficient for processing large numbers of patient samples.

Buffers↗
PubMed1980

Pharmacokinetics of pertechnetate administered after pretreatment with 400 mg of potassium perchlorate: concise communication.

The pharmacokinetic behavior of pertechnetate in normal subjects has been studied. Each received 400 mg of potassium perchlorate 30 min before pertechnetate injection. Timed blood samples were collected and counted. The time-activity curves for whole blood and plasma could both be fitted to an open two-compartment model of the form 3 comes from 1 in equilibrium with 2, where Compartment 1 refers to the vascular pool, Compartment 2 to the perivascular pool, and Compartment 3 to the urine. The pharmacokinetic state equation is given by: leads to X = -KX. Rate constants determined were: k21 = 1.47 hr-1; k12 = 3.11 hr-1; k01 = 0.137 hr-1. The rate constants were the same for the whole-blood and plasma time-activity curves.

Drug Interactions↗
PubMed1983

Carcinoembryonic antigen: assay following heat compared with perchloric acid extraction in patients with colon cancer, non-neoplastic gastrointestinal diseases, or chronic renal failure.

Heat inactivation has been proposed as an alternative to perchloric acid (PCA) precipitation for the extraction of carcinoembryonic antigen (CEA) from human plasma. We examined a commercial RIA kit using heat inactivation, and compared results with those obtained with PCA precipitation. Adequate sensitivity (1.5 micrograms CEA/l plasma), satisfactory analytical recovery of CEA added to plasma, and dilutional linearity of samples found to have elevated CEA concentrations, were demonstrated for the heat-inactivation assay. Between-assay precision was better with the heat inactivation than with the PCA assay. Although the absolute concentration of CEA estimated after heat inactivation was consistently lower than that estimated after PCA extraction of plasma specimens, there was excellent correlation between results obtained with the two methods in colon cancer patients free of disease, colon cancer patients with residual or recurrent disease, patients with benign gastrointestinal disease, and in patients with chronic renal failure. We conclude that the heat-inactivation assay is an excellent alternative to the PCA assay.

Adenocarcinoma↗
PubMed1993

Treatment of amiodarone-induced hypothyroidism with potassium perchlorate.

The antiarrhythmic drug, amiodarone, induces thyroid dysfunction, which is potentially dangerous in cardiac patients. After discontinuation of the drug it takes several months before euthyroidism is restored. The potent antithyroid drug, potassium perchlorate (KClO4), is used successfully to treat amiodarone-induced thyrotoxicosis, but it is less well known as potential treatment in amiodarone-induced hypothyroidism. In this case report we describe the successful use of two courses of KClO4 treatment in a cardiac patient with severe amiodarone-induced hypothyroidism. The mechanisms responsible for the amiodarone-induced hypothyroidism and rationale for the use of KClO4 in this condition are discussed.

Amiodarone↗
PubMed1995

Analysis of ethanol and acetaldehyde recovery from perchloric acid-treated blood.

Recovery of acetaldehyde (0-20 microM) or ethanol (0-50 mM) added to blood and subsequently treated with perchloric acid (PCA) was evaluated using head-space gas chromatography and compared with controls. Using blood from five dogs, < 100% of acetaldehyde and ethanol was recovered from PCA-treated samples. Mathematical models of putative binding mechanisms indicated acetaldehyde partitioned simply between supernatant and PCA-induced precipitate and occupied < 1% of acetaldehyde binding sites on precipitate; ethanol partitioned simply between supernatant and precipitate and occupied > 62% of ethanol binding sites. The mathematical model also indicated acetaldehyde binding is 2500-fold stronger than ethanol binding. These results indicate as much as 46.4% of acetaldehyde may be bound to PCA-induced precipitate formed in whole blood. This loss of acetaldehyde is 3- to 4-fold greater than acetaldehyde loss caused by evaporation from PCA-treated blood.

Acetaldehyde↗
PubMed1996

Ultrastructural study on thyroid glands of Bufo arenarum larvae kept in potassium perchlorate solution.

The ultrastructure of thyroid glands in Bufo arenarum tadpoles was studied with inhibited thyroid function. After hatching, larvae were kept in potassium perchlorate solution, a goitrogenic substance known to prevent absorption of iodine from water or food, resulting in impaired thyroid hormone synthesis. Increased thyroid gland volume and follicular cell height were observed in treated larvae. The changes in size and volume of follicular cells in experimental tadpoles appeared to be mainly a function of the overstimulation of proteinpoietic apparatus. The cell shows a conspicuous development of endoplasmic reticulum and Golgi complex, as well as an increase in number of mitochondria and colloid droplets. These observations in follicular thyroid cells from Bufo arenarum, obtained under such experimental conditions, were interpreted in terms of interruption of negative feedback mechanisms involving the decrease in the thyroxine circulatory level, and therefore the increase in hypothalamo-hypophyseal endocrine secretory stimulation.

Animals↗
PubMed1996

Non enzymatic liver cells isolation: citrate-perchlorate technique.

In the present study we describe a non-enzymatic technique for the isolation of rat hepatocytes by perfusion of liver through portal vein. The perfusion media consist of 1 mM sodium perchlorate, 5 mM sodium citrate, 10 mM glucose, 129 mM NaCl and 0.1% bovine-serum albumin at pH 7.4. After purification through diatrizoate gradient, electron microscopical studies revealed that most of purified hepatocytes were well preserved and presented a normal ultrastructure, thus correlating with previous biochemical results. The present method enables the recovery of metabolically and morphologically normal hepatocytes.

Animals↗
PubMed1997

Sensory innervation of the guinea pig extraocular muscles: a 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate tracing and calcitonin gene-related peptide immunohistochemical study.

The sensory apparatus of the extraocular muscles attains special interest because of the great variation among different species with respect to the proprioceptors. The sensory innervation of the guinea pig extraocular muscles, lacking both muscle spindles and tendon organs, was investigated with a fluorescence double-labelling method. Primary sensory perikarya were assessed by postmortem application of 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (Di-I) to the extraocular muscle nerves. Traced neurons were found in the ipsilateral ophthalmic part of the trigeminal ganglion. This is in line with findings in other species. Calcitonin gene-related peptide (CGRP) was detected immunohistochemically within the trigeminal ganglion. No somatotopic organization was observed for CGRP-like immunoreactive perikarya. Small (maximal diameter below 30 microm), medium (maximal diameter between 30 and 50 microm), and large (maximal diameter larger than 50 microm) trigeminal ganglion cells were found among the primary afferent perikarya from extraocular muscles. Among CGRP-like immunoreactive cells, only small and medium cells were observed. Double-labelling experiments indicated the CGRP content of primary afferents of the guinea pig extraocular muscles. The relationship to former morphological categories of ganglion cells is discussed. Primary afferent neurons with CGRP-like immunoreactivity might have efferent functions and might also be involved in inflammatory processes of extraocular muscles.

Animals↗
PubMed2000

Projections from the hypothalamus to the posterior lobe in rats during ontogenesis: 1,1'-dioctadecyl-3,3,3', 3'-tetramethylindocarbocyanine perchlorate tracing study.

The objective of this study was to determine the schedule of the arrival of the axons from the hypothalamus to the posterior lobe of the pituitary (PL) in rats during ontogenesis by using the fluorescent lipophilic carbocyanine dye 1,1'-dioctadecyl-3,3,3', 3'-tetramethylindocarbocyanine perchlorate (DiI) as a retrograde tracer. After preliminary fixation of the brain, DiI crystals were implanted in the PL on embryonic day 15 (E15), E16, E17, and E19 as well as on postnatal day 2 (P2) and P9. This was followed by a DiI retrograde diffusion along the plasma membrane and subsequent staining of hypothalamic neuronal cell bodies. The supraoptic nucleus (SO) contained an accumulation of fluorescent cells that extended toward the diamond-like swelling of the third ventricle as early as E15. These data suggest that the magnocellular neurons of the SO send their axons to the PL at the very beginning of differentiation, perhaps even before reaching their final position. The initial axons of the neurons of the paraventricular nucleus proper (PV) appeared to reach the PL significantly later, at E17. In addition to the SO and the PV, accessory magnocellular nuclei contributed to the innervation of the PL in perinatal rats. The neurons of the retrochiasmatic accessory nucleus first sent their axons to the PL on E16-E17. Axons that originated from other accessory hypothalamic nuclei reached the PL after birth, suggesting a delay in their involvement in the regulation of visceral functions compared with other magnocellular nuclei. Thus, the axons of magnocellular neurons reach the PL unexpectedly early in embryogenesis, raising the possibility of the functional significance of vasopressin and oxytocin as fetal neurohormones.

Aging↗
PubMed1977

Hydrolysis mechanism of 7-acetylacroninium perchlorate, a novel prodrug of acronine.

7-Acetylacroninium perchlorate was hydrolyzed at 25 degrees by both water enriched with 18O-labeled water and by unenriched water. The acronine obtained was examined by mass spectrometry, which indicated the unusual fact that hydrolysis of this ester proceeded by aryl oxygen cleavage to the extent of about 30% under those mild conditions.

Acronine↗
PubMed2000

Expression and cellular distribution of perchloric acid-soluble protein is dependent on the cell-proliferating states of NRK-52E cells.

To clarify the biological role of kidney perchloric acid-soluble protein 1 (K-PSP1), its expression and intracellular distribution were examined in normal rat kidney epithelial NRK-52E cells. K-PSP1 expression was low during the proliferating phase and high in the stationary phase, and shown to have a negative relationship with the protein-synthesizing activity of the cells. Immunocytochemical studies revealed that K-PSP1 is predominantly located in the cytosol, especially in endoplasmic reticulum and Golgi apparatus of proliferating cells. In the stationary phase, K-PSP1 was not detected immunologically even though protein and mRNA expression were high. This disappearance of reactivity with anti-serum seems to be due to a conformational change in K-PSP1 induced by unknown factors. These results suggest that the role of K-PSP1 is to regulate cell proliferation, and this may be related to a previously reported ability to inhibit protein synthesis.

Animals↗
PubMed2001

Recombinant expression of perchloric acid-soluble protein reduces cell proliferation.

Perchloric acid-soluble protein (PSP) may play an important role in the regulation of cellular physiological functions because it has been highly conserved throughout evolution; however, this role has not been well elucidated. In previous reports, we suggested that PSP regulates cell proliferation. In this study, we examined the effect of PSP expression on proliferation of the normal rat kidney cell line NRK-52E, the rat hepatocyte cell line RLN-10, and the rat hepatoma cell line dRLh-84. Cells transfected with pcDNA-sense-PSP (pcDNA-S-PSP) over-expressed PSP mRNA and protein, and cell proliferation of the transfected cells was suppressed compared with that of cells transfected with pcDNA-empty (pcDNA-E). Cell viability of pcDNA-S-PSP-transfected cells was similar to that of pcDNA-E-transfected cells. Thus, over-expression of PSP suppresses cell proliferation without any influence on cell viability. These findings are the first to report an inhibitory activity of PSP on cell proliferation.

Animals↗
PubMed2003

Potentiometric determination of equilibrium constants of bases and perchlorates of protonated bases in glacial acetic acid using Superquad.

The traditional method of calculating equilibrium constants in glacial acetic acid medium was developed by Kolthoff and Bruckenstein in 1957; thenceforth, and even presently, few alternatives have been made available to undertake such studies. This paper presents the results obtained with the use of the program Superquad to assess the equilibrium constants of various bases and their protonated perchlorate salts in glacial acetic media. A model of formation equilibria is proposed and fed into the program, considering the species present during an acid-base titration. The calculations of the equilibrium constants using Superquad for pyridine and diethylamine are statistically in agreement with those reported in the literature, (for pyridine: pK(B)=5.98+/-0.02, pK( PyHClO4)=5.47+/-0.02 and for diethylamine pK(B)=5.52+/-0.04, pK( DietHClO4)=4.52+/-0.07). With the use of Superquad, the values found for the aniline were pK(B)=6.95+/-0.06 and pK( AnilHClO4)=4.89+/-0.06.

Journal Article↗
PubMed2006

Perchloric acid-soluble protein is expressed in enterocytes and goblet cells in the intestine and upregulated by dietary lipid.

We previously identified perchloric acid-soluble protein (PSP) in the rat liver, kidney, brain and lung, and reported that it appeared to be related to repression of cell proliferation. In the present study, we clarified that PSP was expressed in the intestine, and found that the amino acid sequence of the intestinal PSP was consistent with those of other PSPs present in other tissues. An immunohistochemical study revealed that PSP was expressed in enterocytes and goblet cells, but not in other cell types among the lamina propria epithelial cells. A comparison of the expressions of PSP and proliferating cell nuclear antigen demonstrated that the proliferating cells did not express PSP. Intestinal PSP expression was induced by approximately 3-fold by oral administration of dietary fat. These findings indicate that the proliferation repression activity may be related to renewal of the intestinal epithelium, and that PSP is one of the fatty acid-inducible proteins.

Animal Feed↗